Slow down turbo! Just busting some chops here, no harm intended!
Accuracy is affected by a lot more things than just the barrel, that's just one small part of the big picture. I think we can all agree on that. The bulk of my long range shooting was while humping the M24, it was designed for that. We studied on the little details of why things are the way they are at distance but for the most part I was just good at doing it, it didn't matter much why it worked.
My comment about long barrels was in reference to the heaviest slug available at the time was the brand new Sierra 69gr matchking, the 1/10 twist of the Remmy would keyhole it at 25yds. Alas, no experience with a longer barrel and the newer slugs available now.
When a buddy gets a new rifle I am happy for him and as excited as he is. Doesn't matter if it's a fancy XCR or some plinker Enfield jungle carbine. I don't pass judgment because I feel my rig is superior. It's his preference and if he likes it, great! Once again, all things being equal, marksmanship is mostly mental. If you have confidence in your rig you'll be better off than having that small seed of doubt that says otherwise. If a 20", or a 54", barrel makes that easier, then so be it. Shoot it and have fun I say!
No foul intended here.